This is a very old archetype, one that spans the ages and cultures. It has been called Yggdrasil, the Axis Mundi, and The Tree of Life among other names. Many works of fiction have embraced it quite thoroughly.

The Tree seems to represent the connection that all living things have. It is present when two people make a promise. It is also present just beyond life, where all souls come together. (So it can also represent Eternity.) If something happens to the World Tree, often a new one will be born from a seed; representing rebirth. Compare Ouroboros.

Of course, anything this spiritually significant is very popular to produce evil versions. Evil World Trees often pervert the concept of "oneness" by subverting promises and spiritual connection into absorbing everything into itself.

In Rozen Maiden, the Tree exists in the Dreamworld, and dreamwalkers can get to other people's hearts via it.

In Ah! My Goddess, "Yggdrasil" is the name of the computer system that connects all things. It is also the name of the original World Tree of Norse Mythology, which underlies much of the series. In the the Ah! My GoddessOVA, Belldandy and Keiichi made a promise long ago that affected Yggdrasil greatly.

It also looks like a tree. A very odd kind of tree, with three intertwined trunks that form an endless triple helix.

The Movie has Yggdrasil's existence as simultaneously a tree and the computer that runs reality be a major plot point.

It should be noted that Yggdrasil is the name of a Linux distribution.

In Kimi ga Nozomu Eien (The Eternity That You Wish For, Rumbling Hearts) promises made at a tree on a hill are crucial to the plot.

In Battle Angel Alita, an Orbital Lift threatens to fall down due to the lost of its upper end, thus inflicting massive damage on earth. Main charakter Alita forms herself into a giant lotus petal which reinforces the Lift, thus preventing the apocalyptical downfall.

Neon Genesis Evangelion uses the Kaballistic Tree Of Life. The concept of breaching the barrier that people put around themselves is integral to the plot.

Nearly every Hayao Miyazaki movie has the World Tree in it in some form.

Mahora Academy in Mahou Sensei Negima literally has the World Tree on campus. It is the setting of the last episode, where promises made in the past are remembered, and used as a battery for frequent time travel in the manga. Also in the manga it glows for one week per 22 years, makes confessions of love (or requests for 'deep' kisses) made near it magically binding, and provides enough ambient magic to power an army of robots.

Also, it's one of the most powerful foci for magical energy on the entire Earth. And it has an old gateport to Mundus Magicus beneath it. And in the late 200s / early 300s chapter-wise, the severing of all other gateports and the tremendous influx of chaotic energy from MM is affecting the World Tree, causing it to glow with extreme amounts of power. If/when Mundus Magicus collapses (which, in Ch. 317, it starts doing), the backlash of energy will explode outwards from the Tree, leveling Mahora Academy and - presumably - killing thousands.

Tsunami, the goddess of the Juraian empire in Tenchi Muyo!, is a massive, intelligent tree (though we never see her tree form, which is one of four forms she has[1]). Every Juraian ship has one of her offspring as its heart, often acting as a miniature world-tree for the very natural-looking landscape that makes up the ship's interior.

In X 1999, the promise made between rival-clan onmyouji Sakurazuka Seishirou and Sumeragi Subaru under an enormous cherry tree is the cause of later tragedy.

Inverted in the third Dragonball Z movie: The antagonists come to Earth and plant a seed which sucks the life out of everything and becomes a giant tree that's visible from space in a matter of hours. The main characters have to destroy the tree to stop it from destroying the world, and so that it can't bear a fruit that will give whoever eats it tremendous power.

Futari wa Pretty Cure Splash* Star revolves around restoring the seven fountains that protect a version of the World Tree in the mythological sense. Meanwhile, in town, the Sky Tree is a World Tree more in the sense of this trope, and is the location for many key events.

It's not overly significant, but Ai Yori Aoshi does show a massive tree into which Kaoru and Aoi carved their names and heights as small children (around the time of their Childhood Marriage Promise), and again as adults.

Which becomes hilarious when you connect this to the fact that the Jewel Seeds grant wishes, and realise the Stealth Pun: the guy was wishing for wood.

Or he was pining for her, a pun that still works in Japanese.

The anime adaptation of Maple Story has a World Tree named... The World Tree.

The aliens Eiru and An in the first arc of the second season of Sailor Moon had the Makaiju (bastardized to "Doom Tree" in the dub), which was an evil giant tree that required the energy of humans to live. Eiru and An fed the tree by sending "cardians" (monsters brought to life from cards) to suck energy from humans. Eventually we learn that the tree was originally the progenitor and life source of Eiru and An's people, but after warfare destroyed the population down to only the two survivors, the Makaiju began to die and Eiru and An had no idea of how to restore it. It got corrupted when Eiru and An misguidedly started feeding it life energy from living creatures and became twisted and malignant. The Makaiju asks Sailor Moon to purify it, and is then reborn as a little space sapling, and Eiru and An set off to find a new home somewhere for it.

The Tree of Knowledge from One Piece, which was basically a massive library and was Robin's favorite hangout as a child, as well as the place where her only friends worked. Too bad those World Government dudes destroyed it.

According to Franky, The Thousand Sunny was also built from a massive tree that was in the middle of a battling country. The cannonballs that would constantly hit it gradually made it stronger and stronger.

Princess Tutu has The Oak Tree. It used to be a place where Story-Spinners gathered to train, but was cut down long before the story begins. However, there's a rock one can still touch to connect to the roots of the tree and speak with it. Fakir attempts this, but he's sucked into the tree, which takes him on a trippy,naked philosophical journey while it seems to attempt to make Fakir a new World Tree himself. He almost agrees to it, saying he will "watch over everyone", and is only saved when Princess Tutu calls out to him and he recognizes Ahiru/Duck's voice. A lot of the imagery in the scene fits the legends well, particularly when it shows the tree in its former glory being connected to the gears of the story.

Wolf's Rain features a "tree of the beginning", which the characters pass by just before the final scene.

Romeo X Juliet turns Escalus into one of these. The tree is responsible for keeping Verona afloat. Apparently it also demands sacrifices once in a while. At the end it is destroyed and Verona lands safely in an ocean, due to Juliet's efforts.

Windaria: The 'Tree of Life' in The Valley. Its huge, refered to as the region's 'Guardian Spirit' and is prayed to by the inhabitants for health and happiness.

Most recently in Hunter X Hunter, Ging, Gon's father meets his son at the top of the aptly named World Tree, known to be 1784 meters from the ground. Ging reveals that this World Tree is only a young tree that refused to grow any taller. Makes you wonder how big a fully grown World Tree is in the Hunter X Hunter World...

In Saint Beast, the giant tree that stands in front of the training hall is infused with memories of the angels who spent time there, allowing Kira and Maya to access them and gather courage before taking their first step toward adulthood.

Most of the climatic fights in the Perfect Origin arc in Kinnikuman take place in Unforgiven Yggdrasil, a gigantic tree said to protect Choujin against the deadly Capillaria rays.

An issue of Badger featured an apple from "The Wotan Tree". Since Ygdrassil is supposed to be an ash tree, this is actually a reference to the god Odin (Wotan, from whence we get Wednesday). The scene where a gigantic tree bursts out of a building in the middle of Minneapolis while two martial artists are slugging it out near the top was pretty cool.

In Hellboy, Rasputin's immortality is due to having half of his soul buried under Yggdrassil's roots. On one occasion, after one of his plans is completely ruined, he retreats to the base of Yggdrassil in order to rest.

The film version offers a more scientific explanation: it's a part of the universe that contains the "Nine Realms", nine planets[2] including Earth/Midgard, Asgard, and Jotunheim. It's simply a collection of galaxies that happens to be tree-shaped.

The Fountain pretty much entirely revolves around this trope, particularly the Christian Tree of Life and Mayan World Tree variations. It actually is the titular Fountain of Youth, apparently, since you drink its sap. (Though eating the bark is just as effective.) It can also grant immortality, but probably not the way you'd expect. "Together we will live forever," indeed.

It apparently outlasts Earth and its health is seemingly tied to the health of the planet. It is suggested that the future version of the tree is a seedling planted over Izzy's grave by present-Tom. Before future-Tom put it in a spaceship, the original Tree was planted in a pool of water on top of a pyramid and guarded by a Mayan sacrifical priest with a flaming sword.

The Thor movie (and, by extension, the entire Marvel Cinematic Universe) has one, which binds the nine realms (Earth/Midgard, Asgard, Jotunheim, etc.) together. You can see it hovering as the universe itself during the end credits.

In the Starlight And Shadows trilogy by Elaine Cunningham. To retain her innate drowmagic on surface indefinitely Liriel Baenre follows a rune quest: she must find the sacred tree Yggsdrasil's Child and scratch on its bark rune with unique ancient artifact. Partial subversion: for conventional perception it's just another ordinary tree in big forest.

Figures greatly (if metaphorically) into Neil Gaiman's American Gods. Interestingly, it is implied that there are multiple "world trees" on Earth, though the reason for this is never explained.

There are probably multiple "world trees" because in American GodsAll Myths Are True, and as mentioned below there are plenty of variations on the World Tree.

In Elizabeth Haydon's Symphony of Ages trilogy, the protagonists travel along the root of one of the FIVE world trees, through the center of the planet, to an identical tree on the other end.

In the The Wheel of Time books by Robert Jordan, there is a Tree of Life in the forbidden city of Rhuidean. In a reference to the Norse God Odin, Mat is hanged from this tree as a price for knowledge.

The tree in question, Avendesora, is the last of a human-engineered species of tree called Chora, which were once commonplace, cultivated in groves purely for the calming aura that they produce. A cutting of the Tree was once made, named Avendoraldera, and gifted to another nation by the keepers of Avendesora, where it grew until a very greedy king cut it down to make his throne, an act that sparked the bloodiest war in centuries.

Given that The Tower appears in some form in every universe, but only as a tower in the "keystone" world, and that at least one of these forms is a plant (a rose), it's entirely possible that somewhere it is a literal World Tree.

Moreover, at one point it's suggested the Great Old Onescut down their version of the World Tree and replaced it with the Tower, to make travel between dimensions possible through Magitek. This of course had unforeseen consequences.

In Sharon Lee's and Steve Miller's Liaden Universe, Jelaza Kazone, the gigantic tree that literally lies at the foundation of clan Korval's family tree, and which in modern times is about a quarter of a mile high. The name - Jela's Fulfillment - is a remembrance of the promise that Jela's partner made to him that she would protect the tree - a promise that is considered (according to Val Con, the current head of the family) to have led directly to the colonization of the planet, since she needed a safe place for the Tree. It is an intelligent being (although most outsiders don't seem to be aware of this), and is considered a member of the family.

The Magician's Nephew features a Tree of Life. The White Witch eats an apple to gain immortality, and the title nephew brings back an apple to protect Narnia from her, and then receives an apple that cures his sick mother.

The apple drops a seed in the Real World which grows up to be another tree. When cut down many years later, it is made into a wardrobe for Digory. Meanwhile, the lantern-crossbar thrown by Jadis grows into an eternally-burning gaslamp in the heart of Narnia.

The Magician's Nephew also features the Wood Between the Worlds, which connects all worlds together in a Dark Tower -like fashion.

Discworld, much like Narnia, occasionally mentions Yggdrasil (a world with a World Tree is briefly seen in Equal Rites, along with one surrounded by the Midgard Serpent). More recently in Making Money the Cabinet of Curiosity, an endless magical cabinet where drawers extend from the sides of other drawers, opens out into an enormous fractal tree-shape.

Used metaphorically in the Twenty Minutes Into the FutureSci Fi novel Gradisil by Adam Roberts to refer to the shape of the Earth's magnetic field at the poles, which are used by the characters to propel electromagnetic flight. The title character's name is a misspelling/mispronunciation of Yggdrasil.

In Dan Simmons Hyperion/Endymion-series there is a world called Gods' Grove which consisted of forests of Mammoth-trees and a large world tree. It is burned due to an attack of aggressive aliens; its burned stump is some kilometers high. Later events consist of a Dyson sphere made out of a tree—which is also burnt.

Telperion and Laurelin, the World Trees from JRR Tolkien's The Silmarillion, used to alternately shine with silver and gold light like night and day... until Morgoth and Ungoliant absorbed their power and corrupted the trees. What was left of them was made into the Moon and the Sun. The only pure and untainted light left of them was caught in the Silmarils, made by Fëanor before the incident.

The Two Trees were sufficiently holy (and large) that not only were their (damaged) fruits sufficient to light the moon and the sun, but the Silmarils made from them power the whole mythos. Eventually, one is put in the sky, one is thrown in the ocean, and one falls into a fiery pit with its owner where it burns at the heart of the earth. After Dagor Dagorath it is said the Silmarils will be renunited, and Yavanna will use them to bring the trees back to life.

Also the various White Trees that were either made in the image of Telperion, or descended from its seedlings (depending on which version of the mythology you read). The withered tree of Gondor in The Lord of the Rings is the "son" of the White Tree of Númenor, which is the "son" of the one from Tol Eressëa, which is the "son" of the one from Tirion, etc. Earendil's star is used to create the Phial of Galadriel, making it the reflected light of the Trees two times over.

The eponymous tree in Robert F. Young's The Last Yggdrasil is the last survivor of a species that looks like Exactly What It Says on the Tin, in the middle of what is otherwise apparently near-perfect wheat-growing country. Humans, having settled on the planet, have logged out the rest of the species and are in the process of cutting down the eponymous tree, which used to be significant to the now-extinct native intelligent species' religion. Far too late to keep the tree from dying of the damage it has sustained, the humans deduce that the tree's species was a vital link in the ecosystem, and without it, they will probably lose most of their crops as related species - such as those that keep crop-eating insects in check - in their turn become extinct.

In The Defeat of Gilgames, a science fiction novel based on a short story, features a planet that has it's entire ecosystem controlled by an enormous sentient tree.

Before Episode III, the Expanded Universe of Star Wars had long described the Wookiees' homeworld of Kashyyyk as having an ecology that was like a layered deathtrap. The core was the wroshyr trees, kilometers tall and so massive the entirety of the Wookiees' civilization—every city and town—is built atop just the highest layer of them. Further, they're so big that the further down you go, the ecology notably shifts, becoming harsher (and thus requiring more deadly animals and secondary plants to survive in it). There are several layers, and going down at least two or three for a hunt is a rite of passage for young Wookiees—and only in stories has anyone made it to the bottom layer and come out alive. On top of this, when she visits Leia notices that the branches seem to have grown together, and realizes that all the trees in a cluster, if not in the entire planet, must be one giant organism.

In Garth Nix's "The Keys to The Kingdom" series, book 6 "Superior Saturday" features the four Drasil trees, which hold up (and continues rasising up) the ceiling of the Upper House/Floor of the Incomparable Gardens.

Nancy Farmer's "The Sea of Trolls," being centered around Norse mythology, features Yggdrassil, but goes beyond the norm by stating that all religions are right and each world is just another branch on the great tree.

In the third book of the Iron Druid Chronicles, the fact that the protagonist is the last of the ancient druids is the reason why the vampire Leif wants to recruit him for his mission to kill Thor. An earth druid who passed all the tests and rituals has a direct link to all nature and can use this to climb the world tree Yggdrasil. This essentially gives him a back door to the realm of the Norse gods.

The Soultrees in Spellfall. They are huge (so huge that walkingfrom one end to another may take days), they have magical powers (including providing food and shelter for mages), souls of dead mages house in the tree so their relatives can speak to them, and they have other magical properties...

Subverted / twisted in The Little Prince. The titular hero explains that a regular baobab, if left unchecked, may develop to this for a small planet, which is very bad, since sooner or later, its offspring will tear the planet apart.

In Star Trek: Voyager, the Talaxian afterlife is said to be a giant forest, in which the largest tree is the "Guiding Tree", at which the dead reunite with loved ones.

In Carnivale, The World Tree is, interestingly enough, connected to the Tattooed Man - the evil, Anti Christ-like being also called "the Usher" that Justin Crowe is transforming into - and features greatly in Justin's prophetic dreams of his coming battle with Ben. Justin and Iris make a subversion of the Childhood Marriage Promise under its branches when Justin vows to build his "kingdom" in the valley below, and Iris answers "we'll build it together".

The Norse Yggdrasil, along with similar Slavic and Hindi examples, seems to have a prehistoric common root with the Tree of Life described in the Bible (central tree + snake + special fruit).

World Trees appear in Chinese and North Asian religions.

Older Than Dirt: The oldest embodiment is the Holy Tree of Eridu in Sumeric-Babylonic cosmology.

The Mayan World Tree is a ceiba tree (ceiba is a tropical species).

The Buddha sat under a Bodhi tree for a number of days to gain knowledge. In fact, in Buddhist mythology, it was believed that the exact spot where the Gotama Buddha attained enlightenment was the first place in the world to exist.

There's also the wooden pillar that Osiris was locked in (and reborn from, sort of), in Egyptian myth.

The Torah of Judaism is often called the "Tree of Life".

The Tree of Knowledge of Good and Evil and the cross Jesus hung from before his transformation, both in The Bible.

Almost every shamanistic religion has some sort of World Tree. See The Other Wiki for specific examples.

The Book of Mormon features the first protagonist/narrator Nephi experiencing a vision in a dream, where the point of the vision was to use an iron rod as a guide to the Tree of Life, while ignoring a big building full of wicked people who tried to lead the righteous away from the tree.

In Deadlands, the spirit world is described as a huge tree, with its roots in the eponymous, hellish Deadlands and its top leafy branches implied to reach a vaguely Judeo-Christian heaven. Subverted in that Christian characters are likely to see Mt.Zion instead of a tree.

The Nobilis mythology is cored on a vast world tree. The Earth hangs from one of its branches.

Certain editions of Dungeons & Dragons, most prominently 2nd edition's Planescape setting, featured the 'world ash' Yggdrasil, a huge tree growing inbetween the planes. Its branches ended in portals to other planes, making it one of the major nexus points for travelers of the multiverse (Sigil, the main setting for Planescape, being another such nexus).

4th edition has the World Tree as one of the biggest and most important Primal Spirits; it's the embodiment of the lifeforce of The Multiverse. Not surprisingly, there's an Epic Destiny that revolves around a Primal character ascending to become a guardian of the World Tree.

The Tree of Life, upon which Suldanessellar—the hidden city of the Amnian Elves—is situated is the penultimate location in Baldur's Gate II: Shadows of Amn. The massive tree is deeply connected to the elves' pantheon of the Seldarine and, in some way, their long lifespan.

Yggdrasil is one of the gods in Breath of Fire 3. It has multiple bodies (trees) around the planet, and one of its seeds is actually a party member, Peco.

Seen in the background of the fight against Abaddon in Castlevania: Dawn of Sorrow. Stands out because before and after, you were descending into the Abyss.

The very top of Death's Peak in Chrono Trigger has a tree. Using the Time Egg here allows one to bring Crono back from a timeline where he died.

In the popular Dragon Quest series, an "Yggdrasil Leaf" item will bring back someone from the dead.

Dragon Quest III has a World Tree hidden in the middle of a forest. Locating and examining the correct tree nets you a Leaf.

Dragon Quest VI has the Sacred Tree of Krage, which produces both the usual leaves and Holy Dew, which has its own amazing healing properties. Naturally, this makes it a prime target for the Demon Lord, who tries to eliminate it by brainwashing the entire nearby town into believing they're the Demon Lord...

Dragon Quest IX has the Observatory, a floating island that houses guardian angels known as Celestrians. Their task: to nourish the World Tree Yggdrasil. Legend states that when Yggdrasil bears fruit, the Celestrians will be relieved of their duty and sent back up into heaven. Later on, the tree is revealed to be the goddess Celestria, daughter of the Almighty.

Final Fantasy IX had the "Iifa Tree", which was sort-of in the evil category (the Tree itself was not evil by nature, but it was re-purposed by the Big Bad into doing bad stuff) - it was sitting on top of the magic well souls used to be recycled, so that the Big Bad could use stagnant souls as soylent fuel. It also houses the gateway to the Very Definitely Final Dungeon on Disc 4.

Legend of Dragoon: the god of creation made a giant tree which in turn produced fruit which became the various species of the world. It only laid 107 fruit; no explanation is given for where the other billions of species came from.

Subspecies. This is actually explained, in game, after you solve the puzzle to fight an Optional Boss.

Spyro spends a good bit of the beginning of The Legend of Spyro: The Eternal Night searching for a large tree that both he and his mentor saw in a vision in an ancient (and deadly) grove.

At the climax of The Legend of Zelda: Majora's Mask, the main character enters a giant moon only to find a giant tree on top of a hill, in the middle of a wind-swept field.

The imagery is shown again in the background of the Ocarina of Time Shadow Link battle.

Both of the Oracle Games featured talking trees that played pivotal roles in the plot (they provided a seed to dispel illusions created by that game's Big Bad).

In Skyward Sword, Link grows a tree through the use of Time Travel that has a cure-all fruit, which he uses to cure the Thunder Dragon's ailment.

The backstory of the Myst computer games includes the D'ni culture, who utilized the image of the Great Tree of Possibilities to symbolize the possible Ages that could be reached through their books.

In Riven, a vast tree used to stand on one of the islands. Gehn cut it down and hollowed out the stump to build a prison the size of an apartment. In the Book of Atrus, it is still standing.

Tay, an Age made as a refuge for the people of Riven under Gehn's rule, primarily features a similar tree in which the Moiety live.

In Exile, the Age of Edanna is a giant tree on a forsaken island, within which an entire ecosystem thrives.

In URU, the Watcher's Pub (AKA the "Great Tree Pub") is made from an enormous hollowed-out tree, which happens to be at least a few miles underground. It was practically a holy site in the D'ni civilization.

In Odin Sphere, a prophecy states that the armies of the fire kingdom will invade The Lost Woods of the elves, and be destroyed once they reach the World Tree... Except that there is not and has never been a world tree in the world of Odin Sphere. When the prophecies begin to come true, we learn that the elf queen Mercedes's true name was Yggdrasil, and that she was the World Tree that would stop them. She dies defeating the king of the fire kingdom, and on that spot, an actual world tree grows.

There's the 'Sacred Tree of Konohana' in Okami, which generally gets refered to as 'Sakuya's Tree'. It also has seedlings (known as 'Guardian Saplings') all over the land, which protect the land. Every time Amaterasu revives one, a fruit grows on Sakuya's tree, which can be cut down for a treasure of some sort.

At the end of the best ending of Persona 4, the heroes witness the purified Heart of Mankind; an Eden with ...yes, the Tree in the center.

Phantom Brave has Marona living on an island with the spirit of a very old tree allowing for the existence of Phantoms on the island itself without Marona's presence.

Quest for Glory III features the Tree at the Heart of the World, complete with appropriate mystic connections and rejuvenation powers. It's big enough to have its own waterfalls.

One would be remiss not to mention the Mana Tree, which the plots of the various Seiken Densetsu/Mana games at least partially revolve around.

And in Tales of Phantasia, the protagonists have to revive a dying world tree called Yggdrasil. It's the same tree, by the way.

Don't forget Tales of Symphonia: Dawn of the New World, where the plot revolves heavily around the guardian of the World Tree that comes into existance immediately after Symphonia. It's interesting that he's named Ratatosk, which connects to Norse mythology, which the game takes many ideas from.

The Tales (series) really likes trees - there's also the treetop village of Morle in Eternia, the big tree in Halure in Vesperia and the tree that's grown over the Giant Psistone that holds Iola's soul in Hearts. None of them are exactly World Trees, but they all mark major plot points in their own way.

In the original Tokimeki Memorial, the ultimate goal for the protagonist is to get the confession of love from his chosen young lady (and accept it) under the Legendary Tree on the school grounds on Graduation Day. This would, according to school legend, ensure them "eternal happiness" together, and is the origin of numerous similar scenes in anime and games.

In the first Valkyrie Profile, one recruitable character expresses an interest in Bifrost and Yggdrasil.

There have been several of these in the Warcraft universe. The World Tree, Nordrassil, is badly wounded at the end of Warcraft III, when the Archdruid Malfurion Stormrage uses its power to defeat the demon Archimonde. Before this, the Night Elves had a spiritual connection with it, which granted them immortality. By World of Warcraft, the Night Elves have tried to make a new one, Teldrassil, but it's not going very well. For one thing, it didn't bring back their lost immortality. For another, it was created without nature's blessing and is slowly being consumed by corruption.

Teldrassil serves as the starting area for Night Elf players, holding the Night Elves' capital city, a couple small towns, and various other areas in its branches. This makes it pretty big even by giant tree standards.

And there are no mining nodes on Teldrassil. Of course.

It is also possible to venture out on some of the branches near the edge. Its a loooong way down. It was not unheard of early in the game's history for falling night elves to compose poetry (often sonnets) while falling to pass the time before hitting bottom

In an ironic subversion to the World Tree's traditional message of oneness and interconnection, Teldrassil is situated on an island miles off the coast of Kalimdor, making Darnassus, the major city on it, the most remote racial capital. Furthermore, it's so isolated and irritating to travel to or from that one of the surest things a Mage can do to piss off other players off is to "accidentally" open a portal to Darnassus instead of a place people want to go.

There's also a large tree (apparently a failed world tree) in Grizzly Hills in Wrath of the Lich King, called Vordrassil. It was destroyed by the ancient peoples who once lived there, because it was corrupted by the Old GodYog-Saron when its roots broke through the roof of its prison. The current resident tribe of Furbolgs are trying to re-grow the tree. For various reasons, this is a bad idea.

This is also one theory as to why Teldrassil was corrupted so quickly.

Just to add insult to injury, Teldrassil might not have been needed in the first place. Medivh's ending narration in Warcraft 3 states that "the roots will heal in time", and indeed, a small root is shown growing. The implication is that Nordrassil would eventually be restored to its former glory.

In one of the Warcraft novels, it's stated that "it will take another century or two for the World Tree to regain its former glory and power." Note that Nordrassil is referred to as the World Tree, with capitals, likely because it was the original World Tree and because the Well of Eternity, a massive fount of magical power, is underneath the tree. This draws even further from Yggdrasil, because the Well of Urd is buried beneath Yggdrasil's roots.

Note that Teldrassil is probably a lot bigger than Nordrassil is inside World of Warcraft, although that might just be Gameplay and Story Segregation. It's possible visit Nordrassil in the Caverns of Time, where it is clearly a lot smaller than Teldrassil even though it is still one of the biggest trees in the game. Likewise, it's not possible to visit Nordrassil in the regular game world (or at least, it's not intended by the developers, although some people have worked out ways to do it), but we can see on the map the zone it is within and that entire zone is about the size of Teldrassil. Teldrassil's base is the size of entire mountain ranges, which even on this Patchwork Map should be remarkable, and it's just another starting zone... They Plotted a Perfectly Good Waste.

And come Cataclysm we learn more about both Trees the corruption of Teldrassel was due to sabotage by Staghelm, and Nordrassil has begun to regrow, and the main focus of the new Mount Hyjal zone is preventing the elemental lord of fire Ragnaros from burning the recovering tree to ash.

The tree that predates Nordrassil is G'Hanir, the Mother Tree. Unlike all the others, this one was not located in the mortal realm and was run by the demigoddess Aviana. It served as the afterlife for all winged creatures (including dragons). Then Avianna was reportedly killed by the demons, and G'Hanir supposedly died. A single acorn was saved by the dragons and used to plant Nordrassil.

In Wild ARMs 3, one of the locations is a large technology-heavy tower called Yggdrasill, which was designed to rejuvenate the dying planet on which the game takes place.

A variant of this trope appears in Xenogears; the Yggdrasil is the place where all of the main characters meet, but is a sand-cruiser (and later, every other form of vehicle) rather than a giant tree.

Xenogears had Razael's Tree, which was metaphorical. Named after Cherubim Raziel (who are not as cute as Hallmark would like you to believe,) the "Tree" was a computer database located in the wreckage of the interstellar weapon that created mankind.

The final stage of Mega Man Zero 2 is depicted as this series' Yggdrasill. Upon its roots, a sleeping Original X uses his own body to seal away the Dark Elf. It Gets Worse.

Grandia (the first one) had an evil example: the final form of the Big Bad Gaia is a gigantic tree-like lifeform near the destroyed city of Zil Padon.

In Dragon Age Origins, the Elven Alienage has a large tree called the Vhenadahl, the Tree of the People, in the center that is supposed to be a symbol of their lost homeland Arlathan (maybe). In a subversion, the codex describing the tree mentions that the city elves have forgotten why the tree is so important, and that maintaining it is just a habit now. The codex also claims that other alienages have let their trees die and be chopped up for firewood. This might explain why nobody cares if Dog urinates on it to gain Mabari Dominance.

The Vhenadahl tree in Kirkwall's Alienage seen in Dragon Age II isn't treated any better. Dalish elves such as Marethari and Merrill treat it with reverence at least. Merrill is shocked that people made a Wallop Mallet—a child's toy—from its wood.

Etrian Odyssey. The labyrinth is called the Yggdrasil labyrinth, although it's more of a dungeon in the first game. The Japanese title even directly translates to "World Tree Labyrinth".

Also, the planets which you fight Bugaboom and Major Burrows on in the first Super Mario Galaxy, which both reappear in this game.

The Great Hollow in Dark Souls a massive tree entered in the swamps of Blighttown, the journey through it is one very long descent. And as shown in the Ash Lake, there hundreds more elsewhere beneath the world.

In one episode of Heroes Chronicles (a spin-off campaign pack from Heroes of Might and Magic III), aptly titled "The World Tree", the hero Tarnum is tasked with saving the World Tree, which was the beginning point of life on the planet, but is now under attack by the undead. He spends most of the game in a series of tunnels searching for the Tree, only to find out near the end that the tunnels themselves are the roots of the Tree itself.

In Kingdoms of Amalur: Reckoning, Nyarlim is a sentient tree that is one of the oldest living mortals in existence. In the "The Legend of Dead Kel" DLC the "god" worshipped by the islanders, Akara, is another tree. Akara also reveals that there were once twelve such trees in the world.

Gunnerkrigg Court; the Cherry Tree growing in a decontamination habitat. It's where Annie starts opening up to Kat by telling her about her mother. The environment is noticeably more colorful than anywhere else in the series.

Subverted with Tom Siddell's hometown, which had a bike rack instead.

In this strip of Irregular Webcomic Paris ask Quercus about their legend of the structure of the universe. Since Quercus is a sapient tree, Paris thinks it might involves the World Tree...turns out:

Quercus: No. It involves quantum fluctuations and vacuum energy expansion in a general relativistic framework.

There was a Journal Roleplay called Edensphere, a spooky jamjar game with its two oddities being that all characters have total amnesia, and the whole thing being set in a kind of giant fishbowl with a very large tree growing up through the center.

Employed in "The Swamp", the fourth episode of the second season of Asian-influenced Avatar: The Last Airbender. The protagonists come across a vast, mysterious wetland known as "The Foggy Swamp", which is actually made of one ancient banyan-grove tree. The wetland is a unified, living organism. Its tribal inhabitants base their philosophies on this phenomenon, in believing that everything in the world, living or once living, is connected, and they "all have the same roots and are all branches of the same tree."

The Boondocks has Huey and Jazmine meet under the World Tree occasionally.

The Danny Phantom episode "Urban Jungle" features the plant ghost Undergrowth, who spreads vines and roots throughout Amity Park, overtaking the town and culminating in a giant tree in the center of town.

The entirety of the French CGI movie Kaena: The Prophecy is set amidst the branches of a giant tree that connects two planets together.

The true form of the Pitar from the "Hearts and Minds" episode of Justice Leagueis a colossal tree whose power transforms the barren world of Kalanor into a lush paradise.

Walt Disney World in Florida has the Tree of Life, which is a giant 145 foot tall artificial tree built on the frame of an oil platform. There are many animal shapes carved into the bark that are easy to overlook if you don't know about them. The tree itself has a backstory where a lonely ant planted a seed that grew into a tree that countless animals would congregate. The magic of the tree eventually formed the bark into the forms of the various animal visitors over the years.

The Arbol del Tule/Tule Tree in Santa Maria del Tule, Oaxaca, Mexico is also called the Tree of Life because of the animal-shaped knots and such in its branches. It is also the largest tree in the world by trunk diameter (though not by height or weight).

To impress upon his readers the majesty and nigh-mythical age of the giant Sequoias and Redwoods, John Muir is claimed to have said, "This tree was here when Jesus walked the earth." When you're talking about a plant as tall as a hill and dozens of human lifetimes old, it's not surprising that a mythology should grow up around it.

Not exactly mythical; a few giant sequoias are over 3,000 years old, and the oldest still-living tree is a 4,800 year old bristlecone pine.